Katale Khor is a cave located in Zanjan Province, Iran. It is situated 120 km south of Zanjan city and is about 410 km from Tehran. The name, Katale Khor, means "mount of the sun". Geological studies in 1984 showed that the cave formation dates back to the Jurassic period. It is believed that the cave is connected to Ali Sadr Cave in Hamadan province. The road from Zanjan to Khatale Khor passes Soltaniyeh, an ancient Ilkhanid city. The cave was discovered about 90 years ago.